Many people who have lived in Chiang Mai for decades talk about “..those insects that come out of the ground and fly everywhere”. When you ask “do you mean termites?”, they usually say “no”, thinking of the tiny, white, wingless insects you find in any piece of buried wood.
In fact, after the first serious rain of the season (i.e. about 20 mm of rain), the termites swarm. These are the kings and the queens, which are much bigger and more tanned than their pale wing-less peasants. The royalties do have wings so they can spread to new places. The name of this insect order, which does not exist in Europe, is “Isoptera”, which means “similar wings”, referring to the fact that the four wings look very similar, in contrast to butterflies, beetles, wasps and flies which have very different fore and hind wings. If you observe the swarms by a street light, you will see there is intensive termite mating, and that gecko lizards have the feast of the year. Keeping your lights on at home during this special night of termite swarming is not wise, as your home might be invaded by thousands of termites.
The wings are only used this one night. They are easily shed, and a successfully fertilised queen will find herself a suitable place to raise a new dynasty. If you sleep through the night of the swarms, you will still be reminded of their activity next morning, as there will be heaps of wings under every lamp, and at the markets there will be baskets of fried termites for sale, as human food.
As there are many species of termites, you may experience a couple of swarms during the early rainy season. Also, there are several ant species swarming too. Termites are sometimes called “white ants”, but that name should be avoided as termites are totally different from ants (order Hymenoptera), which are more related to bees and wasps.
Termites do threat any wooden construction in your tropical garden. Although teak and Afzelia have a reputation of being termite resistant, that is not completely true, you need to observe any wooden construction carefully. Most importantly, do not allow the wood to touch the soil. Bamboo and Eucalyptus touching soil will lose their strength and collapse in about ten months. As to termites as pests, that may occur, but quite often when the gardener pulls up a dead young tree or bush, and sees the termites, he just sees the vultures. The assassin might have been a fungus, a borer, a rodent, the sun, a peeing dog or simply death due to lack of water or flooding.
Another interesting observation, is that the number of mushroom species is much lower here in the tropics than in temperate forests. I think it may have to do with the termites, i.e. here the termites remove the fungal substrate very quickly, while in boreal regions there are no termites, and wood degradation is very slow, generating a vast range of fungal species. While the tropics have a lot of biodiversity above ground, the temperate regions have a lot of biodiversity below ground.
A heap of wings in the morning indicates the annual termite swarm. This heap is not arranged, this is how it looked like at Dokmai Garden.